Vulcanization molding of a green tire involves heating of the green tire. This heating is carried out, for example, by generating steam in a main boiler, supplying the heat of the steam into a steam flow passage within a tire mold containing the green tire through a steam pipe disposed in contact with the tire mold to heat the tire mold, and further transferring the heat of the tire mold to the tire. However, the heating using steam is inferior in heat efficiency since the thermal energy of the steam is lost by radiation from the surface of the steam pipe extending from the main boiler to the tire mold. Therefore, a technique for minimizing the loss of thermal energy is disclosed in Patent Reference 1, in which a metallic ring member contacting with a tire mold is induction-heated by applying alternate current to an induction heating coil installed within the ring member, and the tire mold is heated through the heated ring member. According to this technique, rapid heating (boost heating) of the tire mold can be performed due to minimized thermal energy loss, and the tire mold and the green tire can be efficiently heated, compared with the steam heating.
Patent Literature 1: Japanese Patent Laid-Open No. 2001-158020